Air-powered press with automatic pressure release



July 17, 1962 H. M. ROBINSON 3,044,450

AIR-POWERED PRESS WITH AUTOMATIC PRESSURE RELEASE Filed Dec. 22, 1958 5Sheets-Sheet 1 INVENTOR. HERBERT M. ROBINSON ATTORNEYS AIR-POWERED PRESSWITH AUTOMATIC PRESSURE RELEASE Filed Dec. 22, 1958 July 17, 1962 H. M.ROBINSON 3 Sheets-Sheet 2 NNE QNT NS INVENTOR. HERBERT M. ROBINSON.MM%WVM ATTORNEYS July 17, 1962 H. M. ROBINSON 3,044,450

AIR-POWERED PREss WITH AUTOMATIC PRESSURE RELEASE Filed Dec. 22, 1958 3Sheets-Sheet 3 INVENTOR. HERBERT M. ROBINSON EMI WLW ATTORNEYS UnitedStates Patent Oiiice 3,044,450 Patented July 17, 1962 3,ti44,450AlR-PWERED PRESS WITH AUTMATEC PRESSURE RELEASE Herbert .ll/1. Robinson,3591 W. Outer Drive, Detroit 21, Mich.; Fay Robinson, administran-ix 'ofsaid Herbert M. Robinson, deceased Filed Dee. 22, 1958, Ser. No. 'SZAMS6 Claims. (Cl. 121-38) This invention rela-tes generally to improvementsin airpowered presses and, in particular, to an air-powered pressincluding an improved control means and lever operating structure.

It is the primary object of the present invention to provide an improvedair-powered press including an air cylinder and an automatic controlmeans for controlling the admission and exhaustion kof air from saidcylinder at any pre-determined point during the operation of the presswith full power being available and exerted by the cylinder up to saidpoint.

It is another object of the present invention to provide an improvedair-powered press which is compact in construction whereby a shorter aircylinder may be used and a greater mechanical advantage is obtained thanin similar presses made heretofor.

It is still another object of the present invention to` provide animproved air-powdered cylinder having a novel air cylinder and controlmeans and which is simple and rugged in construction, economical ofmanufacture and eicient in operation.

Other objects, features -and advantages of this invention will beapparent from the following detailed description and appended claims,reference being had to the accompanying drawings forming a part of thespeciiication wherein like reference numerals designate correspondingparts of the several views.

In the drawings:

FIG. l is a vertical side elevational view, partly in section, of anair-powered press made in accordance with the principles of the presentinvention;

FlG. 2 is a fragmentary side elevational view of the operating levers ofthe air valve used'in the present invention and showing them in oneoperative position;-

FIG. 3 is a top plan view of the structure illustrated in FIG. l, takenin the direction of the arrows marked 3;

FIG. 4 is a fragmentary right side elevational view of the structureillustrated in FIG. 1, taken in the direction of the arrow marked 4;

FIG. 5 is a fragmentary elevational sectional View of the structureillustrated in FIG. l, taken substantially along the line 5 5 thereof;

FlG. 6 is a partial elevational side view of the press illustrated inFIG. 1 but showing a modified control system Ifor the air cylinder; and,

FlG. 7 is ya fragmentary elevational sectional View of the structureillustrated in FIG. 6, taken substantially along the line 7--7 thereof.

Referring now to the drawings, and in particular to FIGS. l through 5,the numeral 1t) generally designates the C-shaped body of theair-powered press of .the present invention. The body 10 includes thelower or base portion 11 provided with the laterally extended bottom jaw12, and the vertical column portion 13 which cam'es the laterallyextended upper jaw 14. The body base portion 11 is provided with theusual attachment pads 15 through which are formed the holes 16 forattaching the press in place.

As shown in FIG. 1, the bottom jaw 12 functions as an anvil sleeve inwhich is threadably mounted the threaded stud 17 which functions as ananvil. The stud 17 is slotted longitudinally as at 18 and is guided bymeans of the screw 19 projecting into the slot 18. The stud 17 isadjustably locked in place by means of the lock nuts 29. A conventionalpush rod 21 is slidably mounted in the vertical hole 22 in the upper jaw14 and is provided on the lower end thereof with the socket 23 for thereception of a work tool, such as a punch or riveting tool. The worktool would be held in place in ythe socket 2.3 by means of a suitableset screw las 24. The push rod 21 is provided with the Vertical slot 26in which is slidably engaged the inner end of the screw 25 whereby thepush rod is guided for vertical movement.

A pressure link 27 is provided for moving the push rod 21 upwardly anddownwardly. The pressure link 27 is pivotally connected -at lthe lowerend thereof to the upper end of the push rod 21 by any suitable means,as by means of the pivot pin 2S. The upper end of the pressure link 27is suitably pivotally connected at the upper end thereof to the front`end of the rocker arm 29 by any `suitable means, as by means of thepivot pin Sil'.

As shown in FIGS. l and 3, the rocker arm 2.9 is pivotally mounted atthe forward end thereof between the upwardly extended arms 31 and 32 bymeans of the pivot pin 33. The rocker arm 29' is pivotally connected atthe rear end thereof to the front end of the toggle link 34 by means ofthe pivot pin 35. The rear end of the toggle link 34 is pivotallyconnected by means of the pivot pin 36 to the outer end of the first orshort arm of the bell crank, generally indicated by the numeral 38. Thebell crank 38 also includes the second or longer arm 39, the upper endof which is hingedly mounted between a pair of stationary arms as 41 bymeans of the pivot pin 40. The arms 41 are xed'on the upper outer rearend of the body column portion 13. The lower end of the bell crank arm39 is pivotally connected by means of the pivot pin 42 to the outer endof the cylinder rod 43 of the air cylinder, generally indicated by thenumeral 44.

As shown in FIGS. 1, 3 and 4, the air cylinder 44 includes the cylinderor tubular body 45 which is enclosed on the ylower end thereof by thepiston head end cover member 46 and at the upper end thereof by thecylinder rod end cover member 47. The cover members 46 and 47 are ixedlysecured to the cylinder 4S by means of the elongated bolts 4S and thenuts 49. The cylinder end cover 46 is provided with the downwardlyextended integral arm 50 which is disposed between the spaced apartupwardly extended arms 51 and 52 on fthe body base portion 11. The arm5i) is pivotally connectedto the arms 51 and 52 by means of the pivotpin 53.

As lshown in FIG. l, the cylinder rod 43 is slidably mounted in thebushing 54 which is suitably mounted in the hole 55 formed through thecylinder end member 47. The top cylinder end member 47 is provided withIthe vent hole 56 in which is mounted the vent yscreen 57. Slidablymounted in the cylinder 45 is the piston 5S. The reduced inner end 59 ofthe cylinder rod 43 is mounted -through the hole et) in the piston 58and is secured thereto by means of the nut 61 which is seated in theenlarged outer end 62 of the hole 60. The piston 58 -is provided withthe oil wick 63 which is mounted in a suitable annular groove and withthe seal member 64 which is also mounted in :a suitable annular groove.The piston 58 is normally 3 retained in the inoperative position shownin FIG. 1 by means of the return spring 65, the lower end of which isseated in the annular groove 66 formed in the inner face of the piston58 andthe upper end of which is seated in the annular groove 67 formedin the inner face of the cylinder end cover member 47.

As shown in FIG. l, the bottom end cover of the cylinder is providedwith the air passage 63 which communicates with the interior of thecylinder 45. Mounted in the outer end of the passage 68 is the tubingtit-ting 69 in which is mounted one 'end of the tubing 70. The other endot the tubing 70 is mounted -in the Atubing tting 71 which is mounted ina rst port 72 in the air flow control valve generally indicated by thenumeral 73. It will be s-een that the valve 73 is mounted on the pressbody in a position adjacent the air cylinder 44. 'Ihe control valve 73includes Ithe rear body portion 74 and the front body portion l75 whichare secured together by a plurality of body cap 4screws as 77 andbetween which is mounted the body gasket 76. As shown in FIG. 5, thecontrol valve '73 is secured to the press body 10 by means of the spacersleeves 78 and the screws 79 and nuts 30.

A chamber 81 Iis formed in the front valve body portion 75 and movablymounted in this chamber is the con- -trol plate 82. The control plate S2`is ixedly mounted on the inner end of the valve operating plunger 83and this plunger extends outwardly of thevalve body portion 75V throughthe boss 84. The plunger 83 is provided With a suitable seal as 85. Anexhaust conduit 86 is formed in lthe rear valve body portion 84 andcommunicates with a chamber 81, and this exhaust conduit is adapted tobe closed by means of the exhaust valve 87 which is carried n thecontrol plate 82.- The control plate 82 also carries the -xed intakevalve rod 88 which is adapted to unseat the intake valve 89 when the4operating plunger 83 is moved `inwardly of the valve body. The intakevalve is dis-posed in the intake passage 91 and is normally biased to aclosed position to the left as viewed in FIG. 1, by means of the spring90. Fixedly mounted in the outer end of the intake passage 91 is theintake passage cap 92 which is yadapted to be connected to any suitablesource of air under pressure. The laforegoing described structure is aconventional valve available on the market. A suitable valve for thepurposes of this invention is a treadle valve, model F461, xandobtainable from the Robinson Engineering and Sales Co.,V Detroit,Michigan.

The numeral 93 indicates an operating pedal which may be adapted forhand or foot operation and which i-s connected to .the iirst valvecontrol lever 94 by any suitable means, as by the screw 95. As shown inFIGS. 1, 3 and 5, the lever 94 is pivotally mounted on the stationarypost or pivot pin 96 which is iixed on the press tbody column 13 bymeans of the screw 97 and nut 98. The lever 94 is adapted to be held inthe'inoperative position shown in FIG. l by means of 'the return spring99. One end of fixed by means of the screw 101 to the press body. The

other end of the spring 99 is secured tothe pivot pin 102 which iscarried on the upper endv of the lever 94 and which extends sidwardly,outwardly therefrom. A trip bar 103 is pivotally mounted on the pin 102and the rear end lthereof is adapted to be normally engaged in the notch104 formed on Ithe upper end of t-he second valve control lever orplunger lever 105. The lever 105 is disposed adjacent the lever 94 butis spaced apart therefrom and is also pivotally mounted at anintermediate point thereof on the pivot pin 96. The lower endrof thelever 105 is pivotally mounted to the outer end of the valve operatingplunger 83v by any suitable means, as -by means ot the pivot pin 106.The lever 105 is ladapted to be ,normally held againstV the trip `bar103 by means 'of the return spring 107. TheV spring 107 is secured tothe upper end of .the lever 105 as at 108, and to the valve body 10 asat the point 109. l Y

As shown in FIGS. 1, 3 and 5, a bracket 110 is xedly secured by means ofthe screw 111 to the rocker arm 29. The bracket 110 includes the loweroutwardly extended horizontal arm 112 which may be termed a `fork armand which is provided with the slot 113 into which is engaged thevertical control rod 114 when the rocker arm 29 is moved about 'itspivot pin 33 in a counterclockwise direction as viewed in FIG. l. Anadjustable stop member 115 is secured on the upper end of the rod 114 bymeans of the set screw 116. The rod 114 is slidably mounted through thehole 117 in the boss 118 whichV is mounted on the upper end of the pressbody 10. The lower end of the rod 114 is slidably mounted through thevertical hole 119 in the bracket 120 which is Xedly secured to the pressbody wall 13 by means of the screws 121 and nuts 122. An adjustable stop123 is mounted on the rod 114 by means of the set screw 124 and thisstop limits the downwardly movement of the rod'114 relative to thebracket 120. A trip lever 125 is pivotally mounted on the lowerbifurcated end of the bracket 120 at an interasV the spring 99 isconnected tothe bracket 100 which is mediate point thereof as at 126. Astop member 127 is mounted on the extreme lower end of the rod 114 and aspring 128 is mounted on the rod 114 between the bracket and the triplever 125. The spring 128 functions to normally press the inner .end ofthe lever downwardly which in turn forces the stop 127 and the rod 114downwardly. Adjustably mounted on the outer end of the trip lever 125 isthe cam screw 129 which is secured in place by means of the lock nut130.

In operation, the pedal 93 would be depressed and the levers 94 and 105would be pivoted counterclockwise around the pivot pin 96 as viewed inFIG. 1. This action will cause the valve plunger 83 to be moved inwardlywhereby the'exhaust valve 87 will close the exhaust passage 86 and theValve rod 88 will unseat the intake valve 89 to permit air underpressure to pass into the valve and through the tubing 70 and into thecylinder 44 and into operative engagement against the piston 58. The rod43 will be moved upwardly as viewed in FIG. 1 whereby the bell crank 38will be pivoted around the pivot pin 40. The lever 34 will in turn bemoved by the bell crank 38 `and will rotate the rocker arm 29counterclockwise about its pivot pin 33.V The rocker arm 29 operates thepressure link 27 downwardly which in turn moves the push rod 21downwardly for an operation. As the rocker arm 29 is rotated, the forkarm 112 will engage the rod 114 and at a predetermined point in therotation of the rocker arm 29, the fork arm 112 will engage the stopmember 115 whereby the control rod 114 will be lifted upwardly againstthe pressure of the return spring 128. When the rod 114 ismovedupwardly, the stop 127 on the lower end thereof will engage thetrip lever 127 and will rotate Vit counterclockwise as viewed in FIG. 5,whereby the screw 129 willmove downwardly and engage the cam nose on thetrip bar 103 and pivot this bar clockwise as viewed in FIG. l. Thisaction will pivot the rear end of the trip bar 103 out of the notch 104on the lever 105. The lever 10S will be then moved clockwise as viewedin FIG. 1, by means of the action of the return spring 107 and to theposition as shown in FIG. 2. The operating plunger 83 will be movedoutwardly of the valve body or to the left as viewed in FIG. l.

When the valve plunger 83.is moved outwardly this action moves theexhaust valve 87 to the left, as viewed in FIG. l, to unseat this valveand open the valve chamber 81 to the atmosphere. The return spring 90also moves the intake valve 89 to the closed position to cut off thesource of under pressure. VThe return spring 65 then moves the piston 58downwardly back to the rest position as shown in FIG. l and the lair inthe cylinder 45 will be exhausted to the atmosphere through the tubing70 to the valve chamber 81 and out through the conduit 86.

It will be seen that the press is automatically released at anypre-determined point in its travel depending on the setting of the stopmember 115 on the control rod 114. The press is capable of supplyingfull power u yto the release point and a quick release operation is theneffected due to the location of the control valve 73 in close proximityto the air cylinder 44. n The control system of the present inventioneliminates the need for any cushioning means in the air cylinder.

FIGS, 6 and 7 illustrate the press of FIGS. 1 through 5 as provided witha control system which is slightly modiiied from that of the iirstembodiment previously described. The corresponding parts of theembodiment of FIGS. 6 and 7 have been marked with the same referencenumerals followed by the small letter a. In this second embodiment thetrip lever 125 and cam screw 129 have been replaced with an electricallyoperated solenoid plunger for actuation of the trip bar 103.

The numeral 131 indicates generally a conventional electrical solenoidmounted in the box 132 on the press body a. The solenoid 131 includesthe plunger 133 which is adapted to engage the trip bar 10311 forreleasing the lever 105a whereby the valve 73a will operate in the samemanner as valve 73. The plunger 133 is normally held in the upwardlyretracted position shown in FIG. 6 by means of the spring 134. Theplunger 133 is secured to the solenoid armature rod 135 which is adaptedto be moved downwardly in the usual manner when the solenoid coil 136 isenergized. The solenoid coil 136 would be energized by means of theconductors 137 and 138 which would be connected to any suitable sourceof electrical power. The ilow of power to the solenoid coil 136 would becontrolled by means of a suitable micro switch, generally indicated bythe numeral 140, which would be provided with two suitable contacts as139 to make and break the circuit through one of the conduits as 138. Asshown in FIG. 6, the lower end 141 of the control rod 114a wouldnormally hold the contacts 139 open, whereby the solenoid 131 would beinoperative. The control rod 114:1 would be held downwardly in theinoperative position by means of spring 142 bearing against the stopmember 143 on the lower end of the Y rod 114:1.

The second embodiment of the invention as shown in FIGS. 6 and 7operates in substantially the same manner as the previously describediirst embodiment. The only dilerence is that when the control rod 114@is moved upwardly by means of the fork arm 11211, the contacts 139 willengage each other since they are spring mounted, and the solenoid coil136 will be energized. The solenoid armature plunger rod 135 will thenbe moved downwardly and the plunger 133 will in -turn be moveddownwardly into operative engagement with the trip bar 103er. Theensuing action is then the same as the aforedescribed releasing actionof the first embodiment.

While it will be apparent that the preferred embodiments of theinvention herein disclosed are well calculated to fulfill the objectsabove stated, it will be appreciated that the invention is susceptibleto modification, variation and change without departing from the properscope or fair meaning of the subjoined claims.

What I claim is:

l. In an air-powered press, the combination of, a press body; a push rodmovably mounted on said press body for carrying a work tool; a rockerarm pivotally mounted on said press body for moving said push rod; anair cylinder mounted on said press body and including la piston and apiston rod connected to said piston and extending through the upper endcover of the cylinder; means connecting said piston rod to said rockerarm for rocking the same when the piston rod is moved outwardly of thecylinder; a spring in said cylinder for normally maintaining said pistonin an inoperative position at the lower end of the cylinder; an air flowcontrol valve mounted on said press body adjacent the air cylinder andbeing connected to the lower end of the cylinder for admitting air underpressure to the cylinder for moving the piston against the pressure ofthe spring in the cylinder and for exhausting the air from the cylinder;said `air flow control valve including a chamber and exhaust valve forexhausting the chamber to the atmosphere and an alternately operableintake valve for admitting air under pressure into said chamber from asource of pressurized air; a tube connecting said chamber and saidcylinder for conducting air under pressure from said chamber to saidcylinder for moving said piston and for exhausting said cylinder to theatmosphere through said chamber and exhaust valve; lever means formanually opening said intake valve and closing said exhaust valve,whereby, air under pressure will be admitted into the cylinder tooperate the press and rock said rocker arm;and, means for automaticallyoperating said lever means to close said intake valve and open saidexhaust valve after a predetermined rocking movement of said rocker arm.

2. In an air-powered press, the combination of, a press body; a push rodmovably mounted on said press body for carrying a work tool; a rockerarm pivotally mounted on said press body for moving said push rod; anair cylinder mounted on said press body and including a piston and apiston rod connected to said piston and extending through the upper endcover of the cylinder; means connecting said piston rod -to said rockerarm for rocking the same when the piston rod is moved outwardly of thecylinder; a spring in said cylinder for normally maintain-l ing saidpiston in an inoperative position at the lower end of the cylinder; anair flow control valve mounted on said press body adjacent the aircylinder and being connected to the lower end of the cylinder foradmitting air under pressure to the cylinder for moving the pistonagainst the pressure of the spring in the cylinder and for exhaustingthe air from the cylinder; said air iiow control valve including achamber and exhaust valve for exhausting the chamber to the atmosphereand an alternately operable intake valve for admitting air underpressure into said chamber from a source of pressurized air; a tubeconnecting said chamber and said cylinder for conducting air underpressure from said chamber to said cylinder for moving said piston andfor exhausting said cylinder to the atmosphere through said chamber andexhaust valve; a plunger rod in said lair ilow control valve foroperating the exhaust and intake valves; a irst spring biased leverconnected to said plunger rod and being normally biased to a rstposition to open the exhaust valve and close the intake valve; a secondspring biased lever releasably connected to said tirst spring biasedlever and being manually operable to move the first spring biased leverto a second position to close the exhaust valve and open the intakevalve to admit air under pressure to the cylinder to operate the pressand rock said rocker arm; and means operable by said rocker arm fordisconnecting said spring biased levers, whereby, said first springbiased lever returns to said first position and said exhaust valve isopened and said intake valve is closed, and, the spring in the aircylinder moves the piston back to the inoperative position.

3. The structure as defined in claim 2, wherein: said means operable bysaid rocker arm for disconnecting said spring biased levers includes apivotally mounted trip lever operable when pivoted in one direction todisconnect said spring biased levers, and, a control rod connected tosaid trip lever and movable by said rocker arm for pivoting the triplever in said one direction to disconnect said spring biased leversafter a predetermined rocking movement of said rocker arm.

4. The structure as defined in claim 2, wherein: said K means operableby said rocker arm for disconnecting said spring biased levers includesan electrically operated solenoid for disconnecting said spring biasedlevers, and, a control rod connected to said solenoid and movable bysaid rocker arm for energizing the solenoid to disconnect said springbiased levers after a predetermined rocking movement of said rocker arm.

5. The structure as defined in claim 2. wherein said means connectingsaid piston rod to said rocker .arm includes a pivotally mountedbellcrank connected to said piston rod; and, a lever pivotally connectingthe one end thereof to said bell crank and at the other end thereof toAsaid rocker arm. Y Y

6. In an air-powered press, the combination of, a press body; a push rodmovably mounted'on said press body for carrying Ia Work tool; a rockerarm pivotally mounted on said press body for moving said push rod; anair cylinder mounted on said'press body and including a piston and apiston rod connected to said piston and extending through the upper endcover of the cylinder; means connecting said piston rod to said rockerarm for rocking the same when the piston rod is moved outwardly of thecylinder; Ya spring in said cylinder for normally maintaining saidpiston in an inoperative position at the lower end 4of the cylinder; anair oW control valve mounted on said press body adjacent the aircylinder and hayinga chamber operable for admitting -airunder pressureto the piston end thereof and exhausting air therefrom; a manuallyoperated control meansv for operating said air Valve to admit -air underpressure tothe cylinder through said chamber; and, means operated bysaid'rocker arm for operating the air flow control valve to exhaust theair from the air cylinder through said chamber.

References Cited in the tile of this patent UNITED STATES PATENTS Y1,692,771 Ferris Nov. 20, 1928v Y FOREIGN PATENTS 693,892 France Nov.26, 1930 543,946 Great Britain e Mar. 20, 1942

